News Releases

KNOXVILLE, Tenn.— The first cases of West Nile Virus (WNV) in horses in Tennessee in 2003 have been reported in Blount and Hamilton counties.

“Neither of the two horses that tested positive for WNV had been vaccinated for WNV,” said Dr. Frederick Harper, University of Tennessee Extension horse specialist. “One horse had never been vaccinated for any arboviruses including Eastern and Western Equine Encephalitis.” Eastern Equine Encephalitis was recently reported in an Anderson County horse.

“The WNV vaccine appears to be 94-98 percent effective,” said Harper. “Data from a 2002 Kentucky study indicate that most of the horses that died of WNV had not been vaccinated.

There is no known treatment for WNV in horses. Owners who have not vaccinated their horses or given them a booster injection in 2003 should contact their veterinarian, said Harper. Late summer and fall have been when a large number of WNV horse cases have occurred. The cases reported in Blount and Hamilton counties are about a week later in the year than when the first 2002 case occurred on July 24.

For more information on WNV Vaccination Protocol, visit http://animalscience.ag.utk.edu/horses/WestNileVirus.htm.

Horse owners are also urged to vaccinate for Eastern and Western Equine Encephalitis which are also diseases transmitted by mosquitoes. The death rate for horses from EEE exceeds 90 percent, while that for WNV is 30 percent.

Vaccination for WNV does not protect against EEE, and horses vaccinated for EEE are not protected against WNV, Harper said.

To keep up to date on the current WNV horse and bird situation in Tennessee check the UT Department of Animal Science Web site, http://animalscience.ag.utk.edu/ or contact your county Extension office.

# # #

Contact: Dr. Frederick Harper 865-974-3188; Samantha Hill or Patricia McDaniels 865-974-7141